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- Hvarfner, Andreas, et al.
(författare)
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Interactions between indices of calcium metabolism and blood pressure during calcium infusion in humans
- 1989
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Ingår i: Journal of Human Hypertension. - 1476-5527. ; 3:4, s. 211-220
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Tidskriftsartikel (refereegranskat)abstract
- Calcium plays a central role in maintaining vascular tone. Recent studies indicate that there are continuous relationships between systemic calcium metabolism and BP, as over the whole range of normal and raised BPs there is an inverse correlation between plasma ionised calcium concentration and BP. Twenty-two subjects with normal or moderately elevated BP participated in the present study, undertaken to investigate the interactions between systemic calcium metabolism and BP during a two-hour constant-rate calcium infusion in the absence and in the presence of concomitant verapamil infusion. During the infusion there was an increase in plasma ionised calcium by 0.40 mmol/l, SBP rose by 14 mmHg, and DBP by 9.7 mmHg. Higher basal plasma ionised calcium and lower basal serum parathyroid hormone concentrations were associated with a more pronounced diastolic pressor response to the calcium infusion. A greater DBP increase was also accompanied by more pronounced parathyroid hormone suppression, determined as cyclic adenosine monophosphate excretion, and greater tissue uptake of calcium during the infusion. Conversely, higher basal BPs were associated with greater tissue calcium uptake during the infusions. This relationship was abolished when verapamil was present. The present findings extend the previous observations of continuous relationships between indices of calcium metabolism and BP and indicate that both a direct effect of the calcium ion and indirect effects, as evidenced by cyclic adenosine monophosphate excretion, affect the BP response to acute hypercalcaemia.
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| 2. |
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| 3. |
- Hvarfner, Andreas, et al.
(författare)
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Indices of mineral metabolism in relation to blood pressure in a sample of a healthy population
- 1986
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Ingår i: Acta Medica Scandinavica. - 0001-6101. ; 219:5, s. 461-468
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Tidskriftsartikel (refereegranskat)abstract
- Indices of mineral metabolism in blood and urine were analysed in relation to blood pressure in 97 healthy subjects aged 16-82 years. In a multivariate analysis, after allowing for the effects of sex, body mass index (BMI) and age, there was an inverse relationship between plasma level of ionized calcium and mean blood pressure (MBP) (beta = -50.0 mmHg/mmol/l P-ionized calcium, p = 0.0005). In univariate analyses MBP also showed statistically significant inverse relationships with plasma ionized calcium, serum phosphate and renal threshold concentration of phosphate; positive relationships to MBP were found for fasting urinary excretion of calcium and cyclic adenosine monophosphate. However, when examined multivariately, only the relation between MBP and plasma ionized calcium persisted. This study supports previous findings of an inverse relationship between blood pressure and serum ionized calcium and extends the observations to the physiological range. It is further evident from this study that BMI and age should be taken into account in analyses of the relationship between blood pressure and mineral metabolism.
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| 4. |
- Joborn, H, et al.
(författare)
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Serum electrolytes and parathyroid hormone in patients in a coronary care unit
- 1989
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Ingår i: Journal of Internal Medicine. - 1365-2796. ; 225:1, s. 9-14
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Tidskriftsartikel (refereegranskat)abstract
- A prospective study was carried out in 499 patients admitted to a coronary care unit (CCU) in order to evaluate the incidence of clinically significant electrolyte disturbances. Low serum potassium values (less than 3.6 mmol l) occurred in 7% of the CCU patients and low serum magnesium values (less than 0.70 mmol l-1) in 6%. Few patients had low values of both these ions (1.9%). In 49 patients the contents of these electrolytes in muscle biopsies were similar to the values of control subjects and were unrelated to treatment with diuretics. Serum calcium was determined in 444 of the patients and was above the reference range in 11 (2.5%). If we consider their concomitant parathyroid hormone (PTH) values, primary hyperparathyroidism was likely to occur in at least seven patients (1.5%). Patients with acute myocardial infarction (AMI) had mean PTH and electrolyte values similar to those of individuals without this disease. In conclusion, the present study indicates that clinically important disturbances of magnesium, potassium or calcium homeostasis are rare among unselected patients admitted to a CCU.
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| 5. |
- Ljunghall, S, et al.
(författare)
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Serum electrolytes and parathyroid hormone concentrations in acute myocardial infarction
- 1986
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Ingår i: Experimental and Clinical Endocrinology. - 0232-7384. ; 88:1, s. 95-100
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Tidskriftsartikel (refereegranskat)abstract
- Serum concentrations of calcium, magnesium, potassium and phosphate can be lowered experimentally by adrenaline, which also can stimulate the secretion of parathyroid hormone (PTH). In order to evaluate the possible clinical importance of these mechanisms serial blood samples were drawn during the first three hospital days in 26 patients with acute myocardial infarction (AMI), a condition known to increase plasma catecholamine levels. During the study period there were no consistent significant changes of the serum electrolytes. The serum PTH levels, however, were significantly raised in the AMI patients already on admission and did not normalize during the observation time. The PTH concentrations were unexplained by infarct size, concomitant diseases or medication. These findings suggest that PTH could be an independent risk factor for AMI.
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